Drug-Eluting Stents for Renal Artery Stenosis Offers Better Outcomes
CHICAGO—Drug-eluting stents (DES) may achieve better outcomes than bare metal stents in the treatment of renal artery stenosis (RAS), according to researchers.
“There has been a lot of controversy [about this], and I think this is good news for the nephrology community. said study investigator Sanjay Misra, MD, Associate Professor of Radiology at the Mayo Clinic in Rochester, Minn. “Careful selection of the patients is the key.”
Hypertensive patients and those with worsening renal function or uncontrolled hypertension have better outcomes with DES, said Dr. Misra, who presented study findings at the Society of Interventional Radiology's 2011 Annual Scientific Meeting.
He and his colleagues examined the clinical outcomes and primary patency rates of 41 patients (18 women) aged 46 to 89 treated with DES for atherosclerotic RAS in arteries 4 mm or smaller in diameter. Patients underwent the treatment because of worsening renal function or uncontrolled hypertension. Interventional radiologists treated a total of 62 renal arteries, of which 17 had bare metal stents inserted. The average follow-up was 34 months. The primary endpoints included loss of primary patency, change in blood pressure (BP), the number of anti-hypertensive medications required, the need for chronic hemodialysis (HD) or renal transplantation, or death.
Post-procedure, the mean systolic BP decreased and the mean diastolic BP decreased in all patients. However, investigators observed no significant changes in mean serum creatinine, kidney size, or resistive index. The primary patency rate associated with DES was 88.5% at 12 months, 75.2% at 24 months, and 66.3% at 56 months. The primary patency rates associated with bare metal stents were 77.9% at 12 months and 48.7% at both 24 and 56 months.
Patients who received only DES became nearly normotensive and their antihypertensive pill burden dropped by about 0.7 pills per day, Dr. Misra said. Their systolic pressure dropped about 30 mm Hg. He observed that patients with small diameter renal arteries were more hypertensive than those with larger arteries.
Two of the 41 patients died as a result of cardiovascular events within 30 days and another two were started on chronic HD six months post-operatively. Post-intervention, a patient developed a renal artery dissection who ended up on chronic HD. In two patients, transient acute renal failure developed after intervention; this appeared to be related to administration of contrast medium.